• Sent and Scent (as in 'dispatch to' and 'receive from' - not quite so clear-cut as the first two pairings, and not the same tense, but opposites nevertheless - thanks Rachel Sharkey).​


• Pair and Pare (to increase by doubling-up, and to reduce by cutting or trimming away - thanks Kari Caron).​


• Words which without changing the spelling or sound have two opposite meanings - There are a surprising number examples of words spelled the same which have two opposite meanings. These words are called autoantonyms, or contranyms or antagonyms, (less correctly contronyms and antaganyms). English language expert and writer Michael Sheehan in his wonderful book Words to the Wise credits Richard Lederer (language and word-play expert and writer) and Charles Ellis (university professor, dermatologist and antagonyms expert) respectively for coining the terms contranym and antagonym. Here are some very common autoantonym (or contranym or antagonym) words:​


• Cap (limit or stop) and Cap (add to or increase)​


• Outstanding (satisfactory - standard exceeded) and Outstanding (unsatisfactory - standard not met). (Thanks J Molloy)​


• Oversight (check, monitor) and Oversight (neglect, forget)​


• Weather (endure - stand test of time or resist storm or pressure) and Weather (erode - wear down or denude).(Thanks L Bell - thanks also for pointing me towards the antagonym term)​


• Clip (join two or more things together as with a paper-clip) and Clip (divide something into two or more pieces, as in clip an article from the paper or clip someone's hair).​


• Dust (remove a layer of powdery substance) and Dust (apply a layer of powdery substance, as in dusting crops or dusting for finger-prints).​


• Trim (add to or embellish, as in trim the Christmas tree) and Trim (cut away something, as in trim someone's hear or a hedge).​


• Cleave (split apart or break) and Cleave (stick or adhere). (See the explanation under cliches origins for more detail.)​


• Ravish (to violently abuse) and Ravish (to delight)​


• Fast (quick) and Fast (stuck tight)​


• Sanction (a permission) and Sanction (a preventative penalty)​


• Sanguine (cheerful) and Sanguine (bloodthirsty)​


• Bolt (secure in place) and Bolt (run away).​


• Garnish (add to - embellish or decorate) Garnish (remove from - as in legally serving notice to seize money or assets). (Acknowledgements to P Merison, G Comstock, C Klahn, and Bill Bryson's book Mother Tongue.)​


• Bound (fixed) and Bound (moving, as in travelling).​


• Left (gone) and Left (remaining).​


• Mad (angry about) and Mad (attracted to).​


• Livid (angry) and Livid (pallid - lacking colour and spirit). (Thanks L Prinos)